Whoever, in middle age, attempts to realize the wishes and hopes of his early youth, invariably deceives himself. Each ten years of a man's life has its own fortunes, its own hopes, its own desires.

A man's shortcomings are taken from his epoch; his virtues and greatness belong to himself.

Few are open to conviction, but the majority of men are open to persuasion

He alone deserves liberty and life who daily must win them anew.

You acquire a language most readily in the country where it is spoken; you study mineralogy best among miners; and so with everything else.

If you don't know foreign languages, you don't know anything about your own.

If I work incessantly to the last, nature owes me another form of existence when the present one collapses.